I am not sure this article defends it’s headline. We are at the bottom, so maybe we are going back up? I was reading this last night hoping there was some reason to believe that our average family size was growing. But this article does not say that.
I think we’ll have to wait until early 2019 for the actual numbers. That said, I think one could look at the quarterly sales of products sold to parents of new borns to get a sense of any baby boom.
I think the first data on a baby boom would come from births as reported by hospitals. I haven't seen any info related to that.